rrTV-PHOTO   New HD TV
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 755 ONLINE 28 EVENTS SEARCH REGISTER  START HERE
 
2 pages [ <<    <    ( 1 )     2     NEXT    >> ]267 viewsPOST REPLY
Gyro Hobbies . E-flite . Next D

.
.
e-E-Sky Honey Bee- Lama- Belt CP- E-Smart > What would happen if ???
 
 
stocky
Veteran
Location: MA, USA

If I were to put slightly longer blades on the HBK2 and they were to slightly encroach into the tail rotor diameter (ie with one blade along the boom and the tail rotor blade pointing forward looking down on the heli the tail rotor blade and main blade would appear to overlap)
I know in theory this is not ideal, but why, danger of a main/tail strike during heavy landing, or will the flight characteristics be adversely affected?
07-20-2008 05:06 AM
 
 
Gregor99
Elite Veteran
Location: Western Wa

Pondered this myself. I think 275mm is the longest safe length without stretching the boom.

http://www.runryder.com/helicopter/t439457p1/
http://www.runryder.com/helicopter/p3588746/

The risk of contact occurs during inverted stops with some backward cyclic.

Canton MO backyard flying club
West Coast Chapter
07-20-2008 05:37 AM
 
 
Gregor99
Elite Veteran
Location: Western Wa

One other thing I've pondered. Use the Xtreme belt with the stock pulley. That will alow you to run a little longer boom.

Canton MO backyard flying club
West Coast Chapter
07-20-2008 05:38 AM
 
 
TJinGuy
Elite Veteran
Location: Socorro, NM - USA

The real worry of longer blades is boom strikes on hard landings with low head speed. At some point you will also hit the tail blades too but I believe boom strikes are the first concern. High head speeds will help by adding to the outward force. I personally believe y oucan run 285mm blades with no tail blade contact. I made a set of 295mm by accident and those were too long. I now have them cut down to 285 and that works fine on my heli.

- Chris

Variety+spice+life+supporting_paper_towel_industry=
King2+Rex450+Protos+Concept30
07-20-2008 06:39 AM
 
 
Gregor99
Elite Veteran
Location: Western Wa

Chris,
Here's what you're going to need to do to convince me about the 285mm blades.

Start from an inverted hover about 50 to 70 feet up.
Go to full positive collective until you are about 15ft off ground,
Go full negatve collective and pull back hard on the cyclic, into a rainbow.

And of course, get it all on video Even if the heli doesn't explode, it'd be great to watch.

Also, I intend on moving to 450 tail blades which bring the sets of blades that much closer.

Canton MO backyard flying club
West Coast Chapter
07-20-2008 07:14 AM
 
 
TJinGuy
Elite Veteran
Location: Socorro, NM - USA

We have been over this before, several of us have put longer blades on the king and we have found that there is no way they will touch the tail blades until about 290mm. You must have a very short belt or something

- Chris

Variety+spice+life+supporting_paper_towel_industry=
King2+Rex450+Protos+Concept30
07-20-2008 02:30 PM
 
 
tryan02
rrProfessor
Location: Canton, Missouri

292mm for me and running just fine but I guess since greggor is into 3D more than scale or sport flying he better stick with no more than 275mm.

heres a link to my next set of blades for the scale king.
http://www.helidirect.com/product_i...roducts_id=4358


And video proof of 292mm for just scale flying.


Canton MO backyard flying club
Club President
Team No funds left.
07-20-2008 02:39 PM
HOMEPAGE  
 
 
stocky
Veteran
Location: MA, USA

so you guys that have "stretched" the HBK2, what belts have you used/tried(aside from Esky and Xtreme 43T)?
07-20-2008 04:49 PM
 
 
Gregor99
Elite Veteran
Location: Western Wa

Here's what caused me to be concerned. The main blades are Align 325s cut down to 275mm. The tail blades are stock plastic (450 blades are about 2-3mm longer). Although you cannot see it from this camera angle, the contact occurs approximately 5mm above the where the blade tip would contact the top of the vertical fin. So if there was a hit, it would be the tail blades first, then the fin, then the boom. I can only imagine how spectacular a blade to blade stick would be.

If you want to run longer than 275mm, I think you'll be fine as long as you never go inverted and keep strickly to mild sport flying. Avoid massive cyclic inputs and never go inverted.

I'm not planning on 3d anytime soon, but inverted will happen at some point. I will be trying inverted on the HBK2 first and I don't like having a heli that will self destruct under stress.



Canton MO backyard flying club
West Coast Chapter
07-20-2008 09:01 PM
 
 
tryan02
rrProfessor
Location: Canton, Missouri

Stocky my King is all stock running 292mm

Greg
You keep stressing inverted its gonna take more than your rainbow to slap blades Dougie done it with 275's on the 13t pinion? I have done popups at full collective on the much heavier jet ranger with 292mm 95% throttle 9 degree pitch with drilled and cobbled King bladeholders on MX400 blades. Cheaper quality than TREX blades so I am positive I have slop in the bladegrips. Although I will side with you on the rex batwings that would not be a smart Idea with more than 275mm.

My vid is proof it can be done and like I said the disc loading is much greater on my scale king than a stock king. But I gues this wont rest till we get a 3D pilot in here to prove it.

Dag Nab it Greg you from the Show-Me-State?

Canton MO backyard flying club
Club President
Team No funds left.
07-20-2008 09:56 PM
HOMEPAGE  
 
 
Gregor99
Elite Veteran
Location: Western Wa

Quote 
But I gues this wont rest till we get a 3D pilot in here to prove it.

Ironically I don't think a single HBK2 owner here is close to 3d. I know it will be a while for me, so I'm not too worried about it now.

We need Doug to get another HBK2 so he can test it for us. You mentioned he already did. I don't remember the details and he hasn't spoken up on the matter.

I'm guessing that pitch pumping won't put as much load on it as dropping inverted then stopping, with a transition into a rainbow. The drop adds kenetic energy that loads up and cones the blades even more than a quick up and down. I know these moves are so far off from our skills, why bother, right? The point is, I don't want a heli that is setup to self destruct under some conditions. With the occassional franic recovery moves (yes I need to some times), its hard to predict how the blades will end up being loaded and how they will tilt.

Unfortunately I've come to love the longer blades and the HBK2 will probably live a much shorter, but happier life as a result.

Canton MO backyard flying club
West Coast Chapter
07-20-2008 11:57 PM
 
 
tryan02
rrProfessor
Location: Canton, Missouri

Well greg if you ever move to scale youll soon find the little 300 heli must have more lift my 300HDX3800 10t is a pooch put a 2100mah pack in your king and start hammering it a bit you'll quickly see what I mean. This next build Ill come down a bit on the blade length but am going with the 400jgf on 10 or 11t. My theory is try it if you get by with it it must of been the right thing to do. I have a reverse mentality for my line of work but Calculations are just that real world experience will beat it every time.

Canton MO backyard flying club
Club President
Team No funds left.
07-21-2008 12:04 AM
HOMEPAGE  
 
 
Gregor99
Elite Veteran
Location: Western Wa

The thought has crossed my mind more than once. I've always liked the MD500 and considered putting a scale fuse on the HBK2. Slider has that really sharp looking blue and yellow one.

BTW, I've been running the Xtreme 400x since Thursday. That thing is a monster compared to the Esky 3800. More headspeed, a lot louder and more current draw. I might need to drop down to 9t to tame it. I'm currently running a 10t on it and am dropping my t.curves to get it back to sane headspeeds and battery performance.

Canton MO backyard flying club
West Coast Chapter
07-21-2008 12:31 AM
 
 
tryan02
rrProfessor
Location: Canton, Missouri

Im working on a 500 now the jet ranger is retired. Im doing a long term build this time one piece at a time till its the way I want it the fiber frame was the first part. to stay on topic blades havent chosen yet looks like 288mm carbons Im going for this kind of look.

Fender should be proud its a darth fuse Im gonna do like a thunder tiger fuse.



Canton MO backyard flying club
Club President
Team No funds left.
07-21-2008 12:35 AM
HOMEPAGE  
 
 
stocky
Veteran
Location: MA, USA

Some web sites show the length of a blade and state from root to tip or from hole to tip or both.

Some do not and just give a length of eg 275mm

Would you expect that this length is from hole to tip even though it is not stated as such ??

Also, any opinion on these ?

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLMA0
07-21-2008 08:33 PM
 
 
tryan02
rrProfessor
Location: Canton, Missouri

I know why cant manufacturers do things the same I dont understand either. I was gonna try those blades but ruled against it since I wanted to try longer ones 292mm. I think the biggest problem with new blades is just having to shim them. I would vote for getting them and letting us know but CF blades arent cheap to replace remember.

Canton MO backyard flying club
Club President
Team No funds left.
07-21-2008 10:33 PM
HOMEPAGE  
 
 
Gregor99
Elite Veteran
Location: Western Wa

I have the HeliMax 275mm blades. Those are what I used as a template for the Align cut down blades I'm currently running. I haven't measured them but will do so later and report back.

I'm new to CF blades so take this for what its worth. I've tried the CF blades on my King and ABSOLUTELY LOVED THEM. They sound amazing, track perfectly and give the heli a very snappy feel. My cut down Align blades are almost as good but not quite. I'm still running the Align woodies but since I'm flying low and next to concrete walls. At some point I hope that I'll feel like "I've earned them". But I don't feel that way yet.

Canton MO backyard flying club
West Coast Chapter
07-21-2008 10:46 PM
 
 
stocky
Veteran
Location: MA, USA

Gregor thanks,

If you could measure them I would be grateful.
As you have already used them as a template it sounds as if they should work.
07-22-2008 01:09 AM
 
 
tryan02
rrProfessor
Location: Canton, Missouri

If they are not too thick youll find longer blades sometimes have thicker roots. And or the hole will be off and the blades wont have room to turn in the grips. Yeah been there done that with the MX400 blades.

Canton MO backyard flying club
Club President
Team No funds left.
07-22-2008 01:21 AM
HOMEPAGE  
 
 
Gregor99
Elite Veteran
Location: Western Wa

Here are the results for the HeliMax blades. (Love that new digital caliper). From the tip of the blade to the bolt hole is a flat 275mm. From the bolt hole to the edge of the root is 11mm. My cut down Aligns used this blade as template so the sizes are the same.

For comparison, the Esky wood blade measures 263mm from tip to bolt hole and the root is 10mm. 1mm doesn't seem like much, but if you are using the plastic head, the feathering shaft will have to be perfectly centered or the Helimax roots will hit the end of the shaft. This isn't a problem with the CNC featheriung shaft as centering is inherent in the design.

Canton MO backyard flying club
West Coast Chapter
07-22-2008 01:40 AM
 
 
2 pages [ <<    <    ( 1 )     2     NEXT    >> ]267 viewsPOST REPLY
Fast Lad Performance . Ace Hobby . Esprit Model

.
.
e-E-Sky Honey Bee- Lama- Belt CP- E-Smart > What would happen if ???
  UPDATE SCREEN   PRINT TOPIC Advertisers 

Subscribe to This Topic

Tuesday, October 7 - 7:53 pm - Copyright © 2000 - 2008 runryder.com | email | link to rr | runryder needs cookie